My aquaponic lettuce is bolting, I am looking into the possible reasons.
I wonder if NPK all high can cause bolting.

In my experience lettuce can bolt when it is not doing to good on the nutrients. It also looks like it is yellowing a bit in this photo AUF. What is NPK?

Still look good man:)

NPK rating (or N-P-K) is used to label fertilizer based on the relative content of the chemical elements nitrogen (N), phosphorus (P), and potassium (K) that are commonly used in fertilizers.

Your right about the yellow since then I added some new Iron and and they are a dark green now

Thank you for let me know what that means:)

I tried close growing plants in my outdoor fish barrel wants and meant I had planted was doing really well but it all ended up turning yellow and then dying quickly. Maybe I was missing iron? I've never really grown anything successfully in water other than fish:)

Here are some videos I did some time back that I am open to some critiquing!

Video 1




Video 2

Maybe the reason for your plant bolting was because there was a deficiency? A lot of the time when a plant thinks it is going to die or it is at the end of it's life, it tries to go to seed almost immediately. Survival of the fittest;)

After talking with the North Carolina Dept of Agriculture that bolting is not a mater or nutrients, to much or to little I am reasonably sure that it is a combination of to much heat and light. The heat comes from the water being 80 deg and the summer ambient heat being >80 <100deg. and the lighting, which is supplemental (T5 HO florescent)is on in the morning and evening for total illumination of 14hr. The lighting the double heat is the cause of the bolting. If I was hydroponic instead of aquapon it would work better because of the cooler water. In my next planting I am trying different types of summer lettuce.

Ah! I am thinking in the dirt:) Ha ha ha!! Yes, the heat can do that with lettuce, especially cold weather lettuces. When I am on this part of the forum I will need to change my mindset.

Have you ever used "chillers" in your system? Maybe something to look into? It may be to much of a pain in the butt but still cool to look into:) They usually use them for saltwater tanks.

Nice- thank you for the research - And For my application I need to keep my electrical use down, more appliances means more solar panels means more $. Then the cost of the lettuce per head goes up. I need to be priced competitively so this can be a profitable system for others to duplicate.

That's why I want to move into a cave- I mean shipping container: easier to keep ambient heat down with AC unit - have you see our vid on that?

No, not yet:) If you get them on youtube you can share the videos here. Facebook will not let use imbed videos from there site onto our forum:(